E-Cigarettes: The Science Behind the Smoke and Mirrors

Abstract

SummaryE-cigarettes are a diverse set of devices that are designed for pulmonary delivery of nicotine through an aerosol, usually consisting of propylene glycol, nicotine, and flavorings. The devices heat the nicotine solution using a battery-powered circuit and deliver the resulting vapor into the proximal airways and lung. Although the current devices on the market appear to be safer than smoking combusted tobacco, they have their own inherent risks, which remain poorly characterized due to widespread product variability. Despite rising use throughout the United States, predominantly by smokers, limited evidence exists for their efficacy in smoking cessation. Pending regulation by the FDA will enforce limited disclosures on the industry but will not directly impact safety or efficacy. Meanwhile, respiratory health practitioners will need to tailor their discussions with patients, taking into account the broad range of existing effective smoking cessation techniques, including pharmaceutical nicotine replacement therapy.

Risk of asthma exacerbation in adolescent users of electronic nicotine delivery systems: a systematic review and meta-analysis

“…21 In addition to chemical dependency, there are some concerns about the deleterious neurocognitive actions of nicotine, confirmed production of carcinogens, and effects on the vascular endothelium with a consequent impact on cardiovascular diseases. 2,6,7,21 Compared to conventional cigarettes, e-cigarette vapor reaches the airways in the same manner and is equally addictive. 2,6,7 Regarding local aggressive action on the respiratory epithelium, many studies indicate specific inflammatory effects and confirm the impairment of innate immune response in the lungs.…”

“…2,6,7,21 Compared to conventional cigarettes, e-cigarette vapor reaches the airways in the same manner and is equally addictive. 2,6,7 Regarding local aggressive action on the respiratory epithelium, many studies indicate specific inflammatory effects and confirm the impairment of innate immune response in the lungs. Exposure to ENDS flavorings results in abnormal activation of lung epithelial cells and β-defensins, dysfunction of macrophage phagocytic activity, increased mucin levels (MUC5AC), and abnormal activation of neutrophil response (NETosis).…”

“…Heating propylene glycol also generates toxic aldehydes such as formaldehyde, acetaldehyde, and acrolein. 2,6 E-cigarette nicotine vapor reaches the airways in the same manner as conventional cigarette vapor, which makes both products equally addictive. In addition to dependency, the neurocognitive actions of nicotine are a cause for concern.…”

Propylene glycol, a major electronic cigarette constituent, attenuates the adverse effects of high-dose nicotine as measured by intracranial self-stimulation in rats

“…In response to the dramatic increase in the popularity of electronic cigarettes (ECs), the Food and Drug Administration Center for Tobacco Products (FDA CTP) recently extended its regulatory authority to these products (Backinger et al, 2016; Barraza et al, 2017; Chang et al, 2017; Cobb and Sonti, 2016; National Academy of Sciences, 2018). Effective FDA regulation of ECs requires characterization of the pharmacological determinants of their abuse liability.…”

Allergic contact dermatitis and electronic cigarettes: Is nickel to blame?

“…An electronic cigarette is a handheld device designed for inhalant delivery of nicotine through an aerosol, usually consisting of propylene glycol, nicotine, and flavourings . Electronic cigarettes have become popular as a potential alternative to help with smoking cessation .…”